Setting mode of communication

ABSTRACT

A method in a communication system is disclosed. In the method a procedure for setting up a communication link between a first user equipment and a second user equipment via a communications network is initiated. Information regarding at least two modes of communication that can be used for communication via the communication link is signalled between the first and second user equipment. An indicator regarding a mode to be used for the communication is also signalled between the first user equipment and the second user equipment. After the signalling steps, a procedure for setting the mode of communication in accordance with the indicator is initiated in at least in one of the user equipment. According to an alternative embodiment signalling for reserving a possibility for at least tow different communication modes occurs between elements of the communication system.

FIELD OF THE INVENTION

[0001] The present invention relates to communication systems, and inparticular to setting the mode of communication between two nodes.

BACKGROUND OF THE INVENTION

[0002] A communication system is arranged for provision of communicationconnections between two or more entities such as user terminal equipmentand/or other nodes associated with the system. The communication maycomprise, for example, communication of voice, electronic mail (email)and text messages, multimedia and so on. A communication system mayprovide communication over a fixed line or wireless interface for userterminals or other nodes. An example of systems carrying wirelesscommunication is the public land mobile network (PLMN). An example ofthe fixed line networks is the public switched telephone network (PSTN).

[0003] A communication system typically operates in accordance with agiven standard or specification which sets out what the various elementsof the system are permitted to do and how that should be achieved. Forexample, the standard or specification may define if the user, or moreprecisely, user equipment or terminal is provided with a circuitswitched (CS) service or a packet switched (PS) service or both.Communication protocols and/or parameters which shall be used for theconnection are also typically defined. For example, the manner howcommunication shall be implemented between the user equipment and theelements of the communication network is typically based on a predefinedcommunication protocol. In other words, a specific set of “rules” onwhich the communication can be based on needs to be defined to enablecommunication by means of the communication system.

[0004] Examples of the different standards and/or specifications forwireless communication include, without limiting to these,specifications such as GSM (Global System for Mobile communications),AMPS (American Mobile Phone System), DAMPS (Digital AMPS), various GSMbased systems such as the GPRS (General Packet Radio Service). The socalled 3^(rd) generation (3G) standards include systems such as theWCDMA (Wideband Code Division Multiple Access) based UMTS (MultipleAccess in Universal Mobile Telecommunications System), IMT 2000(International Mobile Telecommunications system 2000), i-Phone and soon.

[0005] In a typical wireless cellular communication system a basestation of a radio access network serves user equipment such as mobilestations or similar terminal apparatus via a wireless interface. Each ofthe cells of the cellular system can be served by an appropriatetransceiver apparatus, typically, but not always, referred to as a basestation (BS). The base station may be connected to and controlled by acontroller entity. For example, in the GSM radio network a base stationis connected to and controlled by a node referred to as a base stationcontroller (BSC). The BSC node may in turn be connected to andcontrolled by a mobile switching center (MSC), a serving GPRS supportnode (SGSN) or similar facility. It shall be appreciated that thecontroller entities may be provided by means of appropriate serverentities. For example, functions of a MSC may be provided by a MSCserver (MSS).

[0006] The communication link between a user equipment and the network,i.e. the so called user-to-network leg is typically controlled by atleast one controller entity. The leg may be controlled e.g. by means ofa home or a visited MSC or a MSS media gateway (MGW). When setting up acommunication path between two user equipment via the communicationnetwork the communication mode of the legs at both ends of the path areset up and synchronised so that a desired mode of communication can beprovided for the users. For example, the calling user may wish to have aspeech connection or a video or other multimedia connection with thecalled user, and the connection is then set up accordingly.

[0007] The prior art also suggest a fallback behaviour by means of whicha call can be returned to speech mode in case an attempt to establish amultimedia call fails. By means of this feature a calling user does notneed to know whether the called party supports or wants to receive avideo or other multimedia call, because in this case the call wouldautomatically fall back to a speech call. If the fallback feature is notprovided, the call set-up would then simply fail.

[0008] The users may also wish to be able to change e.g. from the speechmode to the multimedia mode during an ongoing call. This is enabled e.g.by means of the so called SWAP scheme wherein users can start the calleither with speech or with multimedia, and then swap from speech tomultimedia and vice versa during the call. More particularly, e.g. inthe SWAP scheme the users can swap from speech to multimedia and viceversa by initiating the change at both end legs of the connection. Theswap between modes needs to be accomplished locally at each of the endlegs between the respective mobile stations and the visited mobileswitching centre entities. This is so since in the proposed solution thefixed network leg between the wireless legs may offer a substantiallyconstant 64 kbit/s transmission throughout a call, that is the mode ofthe fixed leg is not changed even if the mode of the legs needs to bechanged.

[0009] The inventors have found that the change of the modes may notoperate satisfactorily in the prior art communication systems, and thatthe users might wish to obtain an improved solution for the change ofmodes. For example, if the call is done within a 3GPP (third generationpartnership project) Release 4 split core network architecture i.e. in asystem involving elements such as a MSC Servers (MSS) and Media Gateway(MGW) network elements, the swap procedure requires an in-call bearermodification procedure. This procedure is required to be used in orderto be able to dynamically modify characteristics of a user plane (i.e.the Nb interface) connection (codec) between the MGWs associated withthe connection.

[0010] The inventors have found that a multimedia call cannot be startedwhit a speech-only mode provided with the current ISUP (ISDN User part)signalling and BICC (Bearer Independent Call Control), and that thecurrent ISUP and BICC do not support switching (“swapping”) betweenspeech and multimedia modes. Consequently, the synchronisation of thepossible swaps at both end legs of the connection is left to the users.The users, for example, need to agree verbally on the swap. Both usersneed then activate manually an appropriate radio channel modificationprocedure at their terminals or even setup a new call in the desiredmode.

SUMMARY OF THE INVENTION

[0011] Embodiments of the present invention aim to address one orseveral of the above problems.

[0012] According to one aspect of the present invention, there isprovided a method in a communication system, the method comprising:

[0013] initiation of a procedure for setting up a communication linkbetween a first user equipment and a second user equipment via acommunications network;

[0014] signalling between the first user equipment and the second userequipment information regarding at least two modes of communication thatcan be used for communication via the communication link;

[0015] signalling between the first user equipment and the second userequipment an indicator regarding a mode to be used for thecommunication; and

[0016] initiating in at least in one of the user equipment a procedurefor setting the mode of communication in accordance with the indicator.

[0017] According to another aspect of the present invention there isprovided a communication system comprising network apparatus forprovision of a communication media between a first user equipment and asecond user equipment, the communication media consisting of a first legbetween the first user equipment and the network apparatus, a second legbetween the second user equipment and the network apparatus, and anintermediate portion between the first and second legs, wherein the modeof communication in at least one of said legs can be controlled by theassociated user equipment based on instructions signalled to said userequipment from the user equipment associated with the other one of thelegs.

[0018] According to another aspect of the present invention there isprovided a user equipment for communication via a communication system,comprising means for generating and interpreting messages that includeinformation regarding possible modes of communication available for theuser equipment and means for controlling the mode that shall be used forcommunication in accordance with information included in such a message.

[0019] According to another aspect of the present invention there isprovided a method in a communication system, comprising:

[0020] initiating a procedure for setting up a communication mediabetween at least two user equipment;

[0021] signalling from or to a network element of the communicationsystem information regarding at least two modes of communication, one ofthe modes being for use in the beginning of the communication and the atleast one other mode being reserved for possible use during thecommunication via the communication media;

[0022] signalling from or to said network element an indicator regardinga mode selected among said at least two modes; and

[0023] setting the mode of communication in accordance with theindicator.

[0024] According to another aspect of the present invention there isprovided a communication system, said system comprising means forproviding a communication media between at least two user equipment, anda network element for controlling a communication leg of saidcommunication media, said leg being provided between a user equipmentand the communication system, the network element being adapted forsending and/or receiving information regarding at least two modes ofcommunication, one of the modes being for use in the beginning ofcommunication via said communication media and the at least one othermode being reserved for possible use during the communication via thecommunication media, and also for sending and/or receiving an indicatorregarding a mode selected among said at least two modes, and for settingthe mode of communication in said leg in accordance with the indicator.

[0025] According to another aspect of the present invention there isprovided a network element for a communication system, the element beingarranged to control a communication leg provided between a userequipment and the communication system, for sending and/or receivinginformation regarding at least two modes of communication, one of themodes being for use in the beginning of communication via saidcommunication leg and the at least one other mode being reserved forpossible use during the communication via the communication leg, forsending and/or receiving an indicator regarding a mode selected amongsaid at least two modes, and for setting the mode of communication insaid leg in accordance with the indicator.

[0026] The embodiments of the invention may provide a solution wherein avideo or other multimedia call can be started in a less demanding i.e. alower grade mode such as in the speech mode. The lower grade mode may becheaper to use. A swap to multimedia can be made only when required. Areturn to the cheaper speech mode can be made when the multimedia modeis no longer required. The swap may be automatically synchronised andcontrolled without requiring any activation by the users.

BRIEF DESCRIPTION OF DRAWINGS

[0027] For better understanding of the present invention, reference willnow be made by way of example to the accompanying drawings in which:

[0028]FIG. 1 is a schematic presentation of a communication systemwherein the embodiments of the present invention can be applied to;

[0029]FIG. 2 is a flowchart illustrating operation in accordance with anembodiment of the present invention;

[0030] FIGS. 3 to 5 are signalling flowcharts for various embodiments ofthe present invention;

[0031]FIG. 6 is a flowchart illustrating operation in accordance withanother embodiment of the present invention; and

[0032]FIG. 7 shows a further embodiment.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0033] Reference is made to schematic FIG. 1 which shows a communicationsystem wherein the embodiments of the present invention may be employed.More particularly, FIG. 1 shows a circuit switched PLMN network 10 andtwo mobile user terminal equipment, i.e. mobile stations MS A and MS B.The operation of a typical PLMN system, such as those based on the GSM,and various elements thereof is known by the skilled person, and is thusnot explained in any greater detail. It is sufficient to note that eachof the mobile stations MS A and MS B may communicate over a wirelessinterface with a respective base station BS1, BS2 of the communicationnetwork 10. The communication link or media between mobile stations MS Aand MS B consist of the two wireless interfaces and the intermediatecommunication media within the network 10.

[0034] Two controller entities, and more particularly two mobileswitching centres MSC 1 and 2 are also shown. Each of the mobileswitching centres (MSC) may comprise a home MSC or a visited MSC. TheMSCs may be provided with any appropriate controller entity, such as aserver or a more conventional switching entity. The controller entities1 and 2 are for controlling the provision of the wireless communicationlinks for the mobile stations MS A and MS B, respectively.

[0035] The herein described embodiments are implemented by means of theuser terminal equipment MS A and MS B or the apparatus of thecommunication network. The following will describe these possibilities,starting from the solution wherein the change of the communication modeis initiated by means of communication between at least two userterminal equipment.

[0036] A solution that is based on signalling between the user equipmentwill be described first generally with reference also to the flowchartof FIG. 2.

[0037] When a calling user equipment MS A wants the call to start e.g.in the speech mode, the terminal may reserve a possibility to swap lateron to another mode. For example, the user may wish to reserve apossibility to change to a UDI/RDI (Unrestricted DigitalInformation/Restricted Digital Information) video/multimedia mode duringan already established call.

[0038] The calling user terminal equipment MS A may accomplish this bysending two Bearer Capability Information Elements (BCIEs) in a SETUPmessage (e.g. a GMS/UMTS SETUP message). The BCIEs may comprise a‘Speech’ BCIE and a ‘UDI/RDI Multimedia’ BCIE. The BCIEs are preferablyin the order the user of the calling user equipment MS A wishes the callto proceed. For example, the GSM/UMTS SETUP messages are capable ofcarrying two BCIEs. Thus the provision of this feature will notnecessarily require any major modifications of the already existingsetup signalling mechanism.

[0039] The calling user equipment MS A may also send a “speech first”indication. The “speech first” indication is preferably transparent forthe network 10. Instead, the indicator is intended to be used by thecalled user equipment MS B only. According to a possibility the knownUser-to-User Service (UUS) is used for the signalling of the indicatorfrom the calling user equipment MS A to the called user equipment MS B.The User-to-User Service (UUS) is a standard feature that is alreadyimplemented in network elements of a modern communication system.

[0040] The indication can be e.g. a text command like “Speech”, a flagor any other appropriate indicator that can be interpreted by the calledparty user equipment MS B. What is essential is that the called userequipment MS B can interpret the indicator to be able to determine themode that shall be used for the communication. More precise examples ofappropriate indicators, possibilities to signal the indicator andsubsequent operation will be given later with references to thesignalling flow charts of FIGS. 3 to 5.

[0041] After the called user equipment MS B has received the indicator,it may send an acknowledgement thereof and initiate a procedure for thesetup of its end leg into the speech mode. The two user equipment maythen communicate in the speech mode via the network.

[0042] As explained above, a possibility for a multimedia mode wasreserved during the setup procedure. Should the users wish to change tothe multimedia mode, the change can be initiated by signalling anappropriate indicator from one user equipment to another. This can beaccomplished in the direction from the user equipment MS A to the userequipment MS B or vice versa. After the other one of the user equipmenthas received the indicator is activates a procedure for changing themode from speech to multimedia at its leg. After both end legs have beenmodified, the communication continues in the multimedia mode. It may berequired in some applications that the communication path between theend legs is also modified, although this is not the preferred option.

[0043] The following will give with reference to FIGS. 3 to 5 moredetailed examples of the signalling of information between the two userequipment. In the example the MS A is assumed as being the originatinguser and the MS B is assumed as being the terminating user. Thecommunication path via the network is shown to include three separatecontroller entities. These will be referred to as originating exchange1, transit exchange 3, and terminating exchange 2.

[0044] According to a possibility shown in FIG. 3 the indication can besent already in SETUP Initial Address Message (IAM) using the so calledUUS service 1. The UUS service 1 refers to a user to user signallingservice that can be used when signalling call setup messages.

[0045] The IAM is passed through the exchanges 1, 3 and 2. The calleduser equipment MS B then receives the SETUP (IAM) message containing theUDI/RDI request. The reception of a SETUP message as such is an existingfeature of the ISUP and/or the GSM/UMTS, and will thus not be explainedin any greater detail. After reception the MS B may send anacknowledgement in an appropriate message. For example, messages such as‘ALERTING’, ‘Address Complete Message’ (ACM) or ‘CONNECT Answer Message’(ANM) may be forwarded to the calling user equipment MS A.

[0046] The call is then set up as a speech call, as was indicated by theSETUP message. However, the connection in the intermediate network mayuse a UDI/RDI transmission without compression to facilitate an easierswap from speech mode to UDI/RDI Multimedia mode, should this berequired.

[0047] According to a possibility, when the called terminal MS Breceives a “speech” indication, it consequently responds to the SETUPIAM with two BCIEs, such as ‘Speech’ and ‘Multimedia’. The BCIEs may betransported in this order so that the call will start with speech. Thereceiving user equipment MS B may also acknowledge receipt of theinitial speech indication from the calling user equipment MS A (usinge.g. the above mentioned UUS mechanism). Thus the called user equipmentMS B may also reserve the possibility to swap the modes later, ifrequired. The called user equipment MS B may also indicate by means ofthe 1^(st) BCIE which mode to use in the start of the call.

[0048] According to an alternative embodiment, the called user equipmentMS B may respond to the setup messages with a “UDI/RDI first” (i.e.UDI/RDI Multimedia BCIE and a Speech BCIE in this order) and initiate amodification to speech (between itself and the serving network) later,e.g. immediately after the SETUP.

[0049] It is possible that the calling user equipment MS A gets anegative acknowledgement to the “speech” request or does not get anacknowledgement at all. For example, the called terminal or theintermediate network does not support the used signalling mechanism,e.g. the UUS. The calling user equipment MS A may then initiate amodification to UDI/RDI Multimedia (between itself and the servingnetwork). A multimedia call would then result between the two userequipment.

[0050] It is also possible to invoke UUS service 2 in SETUP InitialAddress Message (IAM) and use the UUS service 2 to convey the indicationand the acknowledgement messages in between ALERTING(ACM) andCONNECT(ANM) in a USER INFORMATION(USR) message (this is a User-to-userinformation message). In this case the called user equipment MS B mayrespond to the setup message with a “UDI/RDI first” (i.e. UDI/RDIMultimedia BCIE and a Speech BCIE in this order) and initiate amodification to speech (between itself and the serving network) later,e.g. immediately after the SETUP.

[0051] As shown by FIG. 4a, it is also possible to invoke a UUS service3 in order to communicate indications between the two user equipment.With the UUS service 3 a swap from the UDI mode to speech mode wouldhappen as a first thing during the active phase of the call. That is,even though the call is setup in a multimedia mode it is immediatelychanged into speech mode, and then later on, if required, changed “back”to the multimedia mode.

[0052] The UUS service 3 may be invoked in SETUP(IAM) or, as shown byFIG. 4a, after the active call phase is reached using the so calledFacility Request Message and Facility Accepted Message (FAR and FAA) ofthe ISUP. The indication of the mode and possible acknowledgements maythen be conveyed with a USER INFORMATION(USR) message in the beginningof the active call state.

[0053] Instead of the UUS mechanisms it is possible to use anApplication Transport Mechanism (APM) with an appropriate APM userapplication. The APM is a standard ISUP signalling mechanism, and isthus not described in any greater detail herein.

[0054] The network apparatus such as a MSC (or MSS) may convert theBCIEs from the calling party MS A for the ISUP/BICC and forward themtowards the called party MS B. The ISUP Fallback facility, as definede.g. in ITU-T Q.764, may be requested.

[0055] After the indication of the possibility for at least one furthermode is successfully communicated between the two user equipment, theuser equipment may change i.e. swap between these modes. The followingwill describe possible procedures for a swap from speech to a Multimediaor vice versa during a call.

[0056] As shown by FIGS. 4b and 5, a user may activate his/her userequipment MS A to send a “swap to multimedia” (or “swap to speech”)indication. The indication is preferably transparent to the intermediatenetwork apparatus 1 to 3 and is meant only for the other party of theconnection (MS B). As above, the User-to-User Service (UUS) may be usedfor the signalling.

[0057] The indication can be e.g. a text message or command, a flag andso on. A UUS service 3 may have been invoked already in the SETUP(IAM),or during the active call phase with a FACILITY(FAR & FAA) message.After invocation UUS service 3 can be used in an active phase of a callto convey the swap indications and acknowledgements e.g. by a USERINFORMATION(USR) message. As above, an alternative to the use of the UUSmechanism is to use APM mechanism with a suitable APM user application.

[0058] The called user equipment MS B receives the “swap tomultimedia/speech” indication and, consequently, initiates amodification from Speech mode to UDI/RDI Multimedia mode or fromMultimedia mode to Speech mode. The modification is initiated by theuser equipment and may only concern the leg between the user equipmentMS B and an element of the serving network, such as the serving exchange2. The user equipment MS B may also acknowledge the “swap tomultimedia/speech” indication to the user equipment MS A using e.g. theabove mentioned UUS or the user information message.

[0059] The user equipment MS A receives the acknowledgement and,consequently, initiates a modification from speech to UDI/RDI Multimediaor multimedia to speech between itself and the serving network.

[0060] Thus the connection at both end legs is modified at theinitiative of the respective user equipment MS A and MS B. As mentionedabove, the connection in the intermediate network may all the time use aUDI/RDI transmission without compression to make a possible later swapto UDI/RDI Multimedia easier. However, it shall be appreciated that thisis not a necessity, and that the intermediate leg may also be modifiedin some applications.

[0061] If the user equipment MS A gets a negative acknowledgement to the“swap” request or does not get an acknowledgement at all (i.e. MS B orthe intermediate network does not support the used signalling mechanism,e.g. the UUS), the user equipment MS A stays in the current mode.

[0062] If the UUS is to be used, a user equipment such as a mobilestation and/or an ISDN terminal shall support the swap feature by beingcapable of generating and recognising UUS “swap” messages.

[0063] According to an alternative to the above described solutionwherein signalling was carried between the user equipment, it ispossible to provide a network oriented solution for the swapping betweenthe different modes. This will be described below with reference to theflowchart of FIG. 6.

[0064] When a calling user equipment MS A wants the call to start withspeech, but reserves the possibility to swap to UDI/RDI Video/Multimedialater during the call, it may send two BCIEs (Speech BCIE and UDI/RDIMultimedia BCIE in this order) in the SETUP message.

[0065] A controller entity 1 such as the MSC Mobile services SwitchingCentre or a MSC Server (MSS) may then convert the BCIEs for ISUP/BICCand forward these to another network element, and more particularlytowards to a corresponding network element 2 serving the called userequipment MS B.

[0066] The controller entity serving the MS A sends also a “speech”indication which is transparent to the intermediate network apparatusand is meant for the corresponding network element 2 serving the calleduser equipment MS B. For example, the User-to-User Service (UUS) can beused for this purpose, but such that the message is not sent by theactual user and to another user but between the two serving networkelements 1 and 2. An alternative to the UUS mechanism is the APMmechanism with a suitable APM user application.

[0067] The network element 2 serving the called user equipment MS Breceives the SETUP (IAM) with the UDI/RDI request. The network element 2receives also a “speech first” indication. The serving network element 2may consequently forward the SETUP (IAM) with two BCIEs, i.e. Speech andMultimedia and in this order, towards the called user equipment MS B forsetup of the call in the speech mode. The BCIEs may need to be convertedfrom ISDN to 3GPP format.

[0068] The called user equipment MS B may respond to the SETUP with twoBCIEs, Speech and Multimedia in this order, to start with speech. Thenetwork element 2 serving the called party MS B acknowledges the“speech” indication to the network element 1 serving the calling partyuser equipment MS A. The above discussed UUS may be used also for thispurpose.

[0069] The call is then set up as a speech call. However, the connectionin the intermediate network may use a UDI/RDI transmission withoutcompression to make a possible later swap to UDI/RDI Multimedia easier.

[0070] If the network element 1 serving the calling user equipment MS Agets a negative acknowledgement to the “speech” request or does not getan acknowledgement at all, the network element 1 may initiate amodification to UDI/RDI Multimedia (between itself and MS A).

[0071] When a user of either the calling or the called user equipmentwants to swap from Speech to Multimedia or vice versa during the call,the user may initiate the swapping procedure at his/her equipment. E.g.an In-Call Modification procedure may be used in here, this being anexisting 3GPP feature.

[0072] In accordance with an embodiment a network element (e.g. 1)serving a user equipment (e.g. MS A) initiates the In-Call Modificationand thus starts the modification procedure between itself and the userequipment. The network element may then send a “swap to multimedia” (or“swap to speech”) indication which is transparent to the intermediatenetwork and is meant for a network element (e.g. 2) that serves anotheruser equipment (e.g. MS B). As above, this may be accomplished by meansof a UUS (User-to-User Service) or APM mechanism with a suitable APMuser application.

[0073] When said other network element serving the other user equipmentreceives the “swap to multimedia” (or “swap to speech”) indication, itmay consequently initiate a modification from Speech to UDI/RDIMultimedia or vice versa on the leg between itself and said other userequipment.

[0074] The network element serving the other user equipment (e.g. MS B)may acknowledge the “swap” request to the network element serving therequesting user equipment. The In-Call Modification procedure is thenfinished at this user equipment (e.g. MS A). The connection at both endlegs is then modified.

[0075] As above, the connection in the intermediate network may not needany modification as it may have been set up to use a UDI/RDItransmission all the time without compression to make a possible laterswap to UDI/RDI Multimedia easier.

[0076] If e.g. a network element 1 serving a user equipment MS A gets anegative acknowledgement to the “swap” request or does not get anacknowledgement at all, the network element 1 serving the user equipmentMS A may reject the In-Call Modification and the connection stays in itscurrent mode.

[0077] According to a possibility the controller entity 1 serving theuser equipment MS A communicated with the called user equipment MS Binstead of the network element 2 serving the called user equipment MS B.This may be needed e.g. in a so called “mobile-to-ISDN-terminal” case.

[0078] Signalling between a user equipment and a network element mayalso be required e.g. in instances wherein one party of a call is servedby a packet switched (PS) network while another party B is served by acircuit switched (CS) network, see FIG. 7. In FIG. 7 signalling of therequired indicators occurs between an interworking network element 4 anda user equipment MS A (or the network element serving the userequipment) in communication via a circuit switched environment 10. Theother party of the call is connected to a packet switched communicationenvironment 20, for example to one operating in accordance with theInternet Protocol (IP) or Session Initiation Protocol (SIP).

[0079] It is noted that the above disclosed solution is applicable alsoin a case wherein more than two user equipment are involved in the call,for example in the case of a conference call. User terminals and theconference bridge may swap in a similar manner between operating modes.It is also possible that some of the connections are in the speech modeand some in video/multimedia mode.

[0080] It should be appreciated that whilst embodiments of the presentinvention have been described in relation to user equipment such asmobile stations, embodiments of the present invention are applicable toany other suitable type of user equipment.

[0081] The embodiment of the present invention has been described in thecontext of GSM based systems. This invention is also applicable to anyother communication systems.

[0082] It shall also be appreciated that the principles described withreference to FIGS. 2 to 5 can also be used for provision of othercontrol features. Thus any control instructions may be signalled via alink between a first user equipment and a second user equipment via acommunications network where after in at least one of the user equipmentmay initiate a procedure for provision of control operations inaccordance with said instructions. The initiation may occur e.g. suchthat said user equipment sends a control procedure activation signal tothe network.

[0083] It is also noted herein that while the above describesexemplifying embodiments of the invention, there are several variationsand modifications which may be made to the disclosed solution withoutdeparting from the scope of the present invention as defined in theappended claims.

1. A method in a communication system, the method comprising: initiation of a procedure for setting up a communication link between a first user equipment and a second user equipment via a communications network; signalling between the first user equipment and the second user equipment information regarding at least two modes of communication that can be used for communication via the communication link; signalling between the first user equipment and the second user equipment an indicator regarding a mode to be used for the communication; and initiating in at least in one of the user equipment a procedure for setting the mode of communication in accordance with the indicator.
 2. A method as claimed in claim 1, wherein signalling of the indicator initiates a procedure to change from one mode of communication to another mode of communication.
 3. A method as claimed in claim 1, wherein the indicator provides information regarding the mode of the communication that shall be used as a first mode of communication.
 4. A method as claimed in claim 1, wherein one of the modes is for communication of speech and one of the modes is for communication of multimedia.
 5. A method as claimed in claim 4, wherein one of the modes is for communication of Unrestricted Digital Information (UDI) or Restricted Digital Information (RDI).
 6. A method as claimed in claim 1, wherein the signalling between the first and second user equipment is passed transparently through at least one network element of the communication network.
 7. A method as claimed in claim 1, comprising use of a user-to-user type signalling service for the signalling between the first and second user equipment.
 8. A method as claimed in claim 1, wherein a first communication leg is formed between the first user equipment and a first element of the communication network and a second communication leg is formed between the second user equipment and a second element of the communication network, and wherein the first and second legs are synchronised in response to the signalling of said indicator regarding the mode to be used for the communication.
 9. A method as claimed in claim 1, wherein the mode of communication within the network is set so that the network is capable of handling communication in accordance with each of said at least two modes of communication.
 10. A method as claimed in any preceding claim, wherein the indication of said at least two possible modes is sent in a message generated in accordance with a setup mechanism.
 11. A method as claimed in claim 1, wherein the indicators are sent during setup signalling between setup messages.
 12. A method as claimed in claim 1, wherein the information regarding the at least two modes of communication is signalled by means of bearer capability information elements.
 13. A method as claimed in claim 1, comprising the steps of setting up the communication path first in a multimedia mode, immediately changing the mode into speech mode, and, if required, changing back to the multimedia mode.
 14. A method as claimed in claim 1, wherein at least one of the user equipment communicates via a circuit switched communication network.
 15. A method as claimed in claim 1, wherein at least one of the user equipment communicates with the communication network via a wireless interface.
 16. A communication system comprising network apparatus for provision of a communication media between a first user equipment and a second user equipment, the communication media consisting of a first leg between the first user equipment and the network apparatus, a second leg between the second user equipment and the network apparatus, and an intermediate portion between the first and second legs, wherein the mode of communication in at least one of said legs can be controlled by the associated user equipment based on instructions signalled to said user equipment from the user equipment associated with the other one of the legs.
 17. A communication system as claimed in claim 16, wherein the signalling between the user equipment enables the user of one of the user equipment to activate a change of the mode of communication between speech and multimedia modes.
 18. A user equipment for communication via a communication system, comprising: means for generating and interpreting messages that include information regarding possible modes of communication available for the user equipment; and means for controlling the mode that shall be used for communication in accordance with information included in such a message.
 19. A method in a communication system, comprising: initiating a procedure for setting up a communication media between at least two user equipment; signalling from or to a network element of the communication system information regarding at least two modes of communication, one of the modes being for use in the beginning of the communication and the at least one other mode being reserved for possible use during the communication via the communication media; signalling from or to said network element an indicator regarding a mode selected among said at least two modes; and setting the mode of communication in accordance with the indicator.
 20. A method as claimed in claim 19, wherein the selected mode comprises the mode that shall be used in the beginning of the communication until otherwise instructed.
 21. A method as claimed in claim 19, wherein the selected mode comprises a mode that is different to the mode of communication used at the time of receiving the indicator.
 22. A method as claimed in claim 19, wherein one of the modes is for communication of speech and one of the modes is for communication of multimedia.
 23. A method as claimed in claim 22, wherein one of the modes is for communication of Unrestricted Digital Information (UDI) or Restricted Digital Information (RDI).
 24. A method as claimed in claim 19, wherein the signalling is passed transparently through at least one network element.
 25. A method as claimed in claim 19, comprising use of a user-to-user type signalling service for the signalling between the network element and a second entity associated with the communications.
 26. A method as claimed in claim 19, wherein a first communication leg of the communication path is formed between a first user equipment and the network element and a second communication leg of the communication path is formed between a second user equipment and a second network element, and wherein the first and second legs are synchronised in response to the signalling of said indicator regarding a mode to be used for communication.
 27. A method as claimed in claim 19, wherein the mode of communication within the network is set so that the network is capable of handling communication in accordance with each of said at least two modes of communication.
 28. A method as claimed in claim 19, wherein the indicators are sent during setup signalling.
 29. A method as claimed in claim 19, wherein the information regarding at least two modes of communication is signalled by means of bearer capability information elements.
 30. A method as claimed in claim 19, wherein the user equipment controlled by the network element communicates via a wireless interface.
 31. A communication system, comprising means for providing a communication media between at least two user equipment, and a network element for controlling a communication leg of said communication media, said leg being provided between a user equipment and the communication system, the network element being adapted for sending and/or receiving information regarding at least two modes of communication, one of the modes being for use in the beginning of communication via said communication media and the at least one other mode being reserved for possible use during the communication via the communication media, and also for sending and/or receiving an indicator regarding a mode selected among said at least two modes, and for setting the mode of communication in said leg in accordance with the indicator.
 32. A network element for a communication system, the element being arranged to control a communication leg provided between a user equipment and the communication system, for sending and/or receiving information regarding at least two modes of communication, one of the modes being for use in the beginning of communication via said communication leg and the at least one other mode being reserved for possible use during the communication via the communication leg, for sending and/or receiving an indicator regarding a mode selected among said at least two modes, and for setting the mode of communication in said leg in accordance with the indicator.
 33. A method in a communication system, the method comprising: setting up a communication link between a first user equipment and a second user equipment via a communications network; signalling between the first user equipment and the second user equipment information regarding control operations via the communication link; and initiating in at least in one of the user equipment a procedure for provision of control operations in accordance with said information. 